Since the small molecular organic metallic complexes “Tris(8-hydroxyquinolinato)aluminium” (Alq3) have been prepared by Tang and VanSlyke to serve as an electron transport layer and the “sandwich-type” light emitting layer of the organic light emitting diodes (OLEDs), the electroluminescent element made of the small molecule by vacuum thermal evaporation to form a film has been successfully applied to the displays of some consumer electronics. To achieve a full-color display, the light emitting material of three primary colors with high color purity, a long life time, and high efficiency is required. However, with respect to green and red light emitting material, the blue fluorescent has a wider band gap which impacts on the injection of the carriers (especially on the injection of the electrons) and the balance of the holes and electrons injection, such that the light emitting efficiency and stability of the blue OLEDs are poorer than that of the green and red OLEDs. To further improve the performance of the OLEDs, the need to develop the blue light emitting materials, especially the deep blue light emitting material, is urgent and noticeable.
In terms of design and preparation of the blue light emitting materials, the progress is great. For example, the earlier U.S. Pat. No. 5,935,721A has disclosed that a blue light emitting compound 9,10-di(naphth-2-yl) anthracene (AND) has a naphthalene group at the 9,9 position of the anthracene based on the anthracene as being the central portion to obtain 3.5 cd/A of luminous efficiency and the chromaticity coordinates at a luminance of 100 cd/cm2 is (0.153, 0.228). Also, in the U.S. Pat. No. 5,891,554A in 2004, the blue fluorescent material, having a styrene group as the bridge, and triphenylamine, phenylamine or carbazole aryl as the terminals (such as DSA-Ph, 1-4-di-[4-(N,N-di-phenyl)amino]styryl-benzene), serves as a guest by doping and performs a luminous efficiency of 9.7 cd/A at a current density of 20 mA/cm2, but the color coordinates are located on (0.16, 0.32) in the sky blue field. In addition, some of other blue light emitting materials also have great progress.

Based on these developments, our patent, China patent No. CN 200710031271, discloses a type of blue light emitting material B1 and B2 having asymmetric structures. This type of material has advantages of photoluminescence efficiency in a solid state, high color purity, amorphous properties, good hole-transport properties, and ease of synthesis and purification.

Although the above-mentioned material has advantages, the shortcomings in the electron injection/transport properties of this type of material appear. Therefore, the present invention provides a blue fluorescent organic material having an electron deficient group in the molecular structure to solve the problems existing in conventional technologies and to achieve deep blue color purity in order to provide a full natural color display effect.